(1) Field of the Invention
The present invention relates to a new resin composition containing polyphenylene ether and, more particularly, a molding resin composition which contains polyphenylene ether and cyclopentadiene containing a polar group.
A new and improved resin composition of the present invention serves as a material suitable as a molding material while it maintains its original properties, i.e., it has good melting flowability and imparts good mechanical and thermal properties to a molded body.
(2) Description of the Prior Art
Polyphenylene ether is a thermoplastic resin having high heat resistance and good mechanical and electrical characteristics, as disclosed in Japanese Patent Disclosure No. 50-126800 and U.S. Pat. No. 3,306,874. However, if polyphenylene ether is used as a molding material, workability is degraded since its softening point is too high. As a result, the good properties and characteristics of polyphenylene ether could not be utilized.
A resin composition was previously proposed to improve moldability of polyphenylene ether by adding high-impact polystyrene to polyphenylene ether, and has been used in industrial applications (Japanese Patent Publication No. 42-22069 and U.S. Pat. No. 3,383,435). However, melting flowability of this resin composition is not satisfactory.
Another resin composition was proposed to further improve melting flowability by adding a low molecular weight hydrocarbon resin to polyphenylene ether (Japanese Patent Publication No. 57-13584, and Japanese Patent Disclosure Nos. 58-129050, 58-129051, 59-126460, and 47-3136). Examples of the low molecular weight hydrocarbon resin are aromatic petroleum resin derived from petroleum naphtha, cyclopentadiene resin, aromatic-cyclopentadiene copolymeric resin, and cumarone-indene resin derived from coal tar.
By adding such a low molecular weight hydrocarbon resin to polyphenylene ether, the melting flowability of the resultant composition can be improved. However, there is much room left for further improvement. In particular, if a resin composition includes an inorganic filler such as a glass filter, further improvement is required.